For Two Particles of Masses M₁ and M₂ and Velocities $\times$

Multiple Choice

For two particles of masses m₁ and m₂ and velocities v₁ and v₂, the velocity of the center of mass is

A) (v₁ + v₂) /(m₁ + m₂) .
B) (v₁ . v₂) /(m₁ + m₂) .
C) (v₁ $\times$ v₂) /(m₁ + m₂) .
D) (m₂v₁ + m₁v₂) /(m₁ + m₂) .
E) (m₁v₁ + m₂v₂) /(m₁ + m₂) .